People use home remedies for a variety of reasons — fighting cancer, losing weight, increasing sex drive, or reducing symptoms of illnesses that have few medical treatments available.

Most home remedies or natural therapies, though, haven’t been put through the same rigorous clinical testing you expect from pharmaceutical medications.

So, does that mean you should ignore them completely?

Not necessarily. It’s more a matter of approaching them with a healthy dose of skepticism.

Dr. Harriet Hall, a retired family physician, former Air Force flight surgeon, and author of the SkepDoc column in Skeptic magazine, is one of those leading the charge against medical “treatments” not supported by science.

Like others in the medical and scientific community, Hall is bothered that many questionable home remedies that might once have been called quackery, folk medicine, or fringe medicine now take shelter under the “alternative medicine” umbrella.

“There is no such thing as ‘alternative medicine.’ There is only medicine that has been tested and proven to work, and medicine that hasn’t,” Hall told Healthline. “Alternative medicine is a marketing term, not a scientific one.”

Natural isn’t always healthy

It’s common for people to think that “natural” means healthy.

But many natural things can kill you — asbestos, ionizing radiation from radon, poison hemlock, and deadly nightshade, just to name a few.

As surprising as it may seem, some herbal supplements sold in reputable natural food stores or pharmacies can also harm you, even at doses recommended on the package.

Supplements may be toxic all by themselves, contaminated with another compound that is toxic, or interact with prescription medications.

Despite the risk of dangerous interactions between supplements and medications, only about one-third of people tell their doctor about the supplements they’re taking, according to one study.

Children are especially at risk of poisoning from herbal or dietary supplements.

A study published this summer found that calls made to poison control centers across the country about herbal and dietary supplements increased almost 50 percent between 2005 and 2012.

Dietary supplements were the top reason for the calls, followed by herbal, hormonal, and other products.

Serious medical problems occurred in about 4 percent of these calls. Ninety-five percent of the serious cases were in children under 6 years old. The majority of these poisonings were unintentional.

One reason for the popularity of herbal supplements is that they’re easy to buy — no visit to the doctor or prescription needed. They’re the ultimate health DIY.

There’s also little government regulation of these products. If companies don’t make claims that their product can treat or cure a health condition, the U.S. Food and Drug Administration (FDA) won’t bother with them.

Until there’s a problem.

Last year, the FDA issued a warning that homeopathic baby teething tablets and gels may pose a risk to infants and children.

Homeopathic remedies are based on the idea that “like cures like.” Small amounts of substances — sometimes toxic — are used to cure symptoms that those substances would cause at higher doses.

The teething tablets contained the poisonous plant belladonna, except in higher amounts than listed on the label.

The FDA investigation turned up more than 400 reports of bad reactions to these products over the past six years. Reactions included tremor, fever, and shortness of breath.

In 10 cases, children died.

On top of the dangers of some homeopathic remedies, there’s little evidence that they’re effective treatments for any condition.

The debate over homeopathy, though, isn’t just about a lack of clinical trials.

One guiding principal of homeopathy is that the more you dilute the active ingredient in water or alcohol, the greater the therapeutic benefit.

Critics say that for this to work, we’d have to radically change what we know about biology, physics, and chemistry.

“Homeopathy not only doesn’t work, but couldn’t possibly work,” said Hall.

Home remedies for cancer

Cancer has long been targeted by people promoting natural therapies.

One study estimates that use of complementary and alternative medicine (CAM) by cancer patients in 18 countries rose from 25 percent in the 1970s to 49 percent after 2000. Use of these products was highest in the United States.

Another study found that herbal supplements were the most commonly used home remedy for cancer, followed by homeopathy, vitamin and mineral supplements, medicinal teas, spiritual therapies, and relaxation techniques.

One of the most popular therapies is Essiac tea, which has been promoted as a cancer treatment since the 1920s. This herbal blend contains burdock root, sheep sorrel herb, slippery elm bark, Turkish rhubarb root, and sometimes other ingredients.

Despite its long reputation as an anticancer remedy, no clinical trials of Essiac have been completed and published in a peer-reviewed journal.

Unlike apricot kernel extract, the side effects of Essiac are less severe, but they do include nausea, vomiting, increased bowel movements, and slight headaches.

Another home remedy for cancer is the Gerson method. It involves following a strict diet, drinking lots of fresh fruit and vegetable juices, taking dietary supplements, and giving yourself coffee enemas.

Although some studies on the Gerson method have been published, none were the rigorous randomized clinical trials that are needed to determine if this home remedy actually helps.

Three people have also died as a result of giving themselves coffee enemas. They can throw off your normal blood chemistry if you do them too often.

There are many more home remedies for treating cancer, with side effects ranging from minor to severe.

But even natural therapies for cancer that don’t kill you directly can still kill you.

In a study published earlier this year, Yale researchers looked at the survival rates of 840 patients with breast, prostate, lung, or colorectal cancer.

People who chose to use only alternative medicine treatments had a higher risk of dying compared to those who used conventional cancer treatments, such as chemotherapy, radiotherapy, surgery, or hormone therapy.

There’s also the fact that people spend a lot of money on unproven treatments.

According to the 2007 National Health Interview Survey (NHIS), 83 million adults spent almost $34 billion out-of-pocket on CAM therapies that year. This accounts for 1.5 percent of the total healthcare spending in the United States.

Why people turn to home remedies

One study found that people are more likely to use herbal supplements if they’re uninsured, use more prescription and over-the-counter medications, or have certain health conditions.

Other research has found higher herbal supplement use among women and people with a higher education.

Some of the most common conditions that people try to treat with herbs include colds, stomach or intestinal illnesses, and problems like rheumatoid arthritis, fibromyalgia, and osteoarthritis. These are all conditions that have few effective medical treatments available.

A person’s culture may also influence their use of CAM therapies. For example, botanical medicine is important to many indigenous cultures in Mexico and the Southwestern United States. Chinese herbal medicine has been for centuries by Chinese people and Chinese-Americans.

These studies try to explain why people turn to home remedies in the first place.

But a bigger question is why people use home remedies that don’t have any scientific evidence showing that they’re effective.

The Australian man who developed cyanide poisoning from taking apricot kernel extract — a mix of a supplement he purchased and a brew he made at home — apparently had a “scientific background,” according to an anesthetist at the hospital where he was treated.

His doctors also warned the man about the risks of the extract, saying the cyanide was blocking the cells in his body from getting the oxygen they needed to survive.

He still refused to give up his daily ritual.

Our Paleo brains drive us

In a post on Skeptic, Hall suggests that human evolution has made it easy for us to fall into the trap of thinking that an herb might cure our cancer, that burning a candle in our ear could improve our overall health, or that a homeopathic remedy diluted almost to nothingness might help us have better sex.

First, our brains are designed to look for patterns, even if they’re wrong.

In our distant past, we reacted quickly if we saw a shadow that looked like a lion in the bushes. It’s better to see a pattern that isn’t there than to miss seeing a real lion.

We also tend to listen to what others tell us. If your friend says there are lions on the other side of the hill, often you’ll listen rather than do your own research.

Our emotions — especially fear — can also motivate us to act, such as running away as fast as we can from a lion.

While these traits helped us survive in a world without technology, they can get us into trouble today.

If a friend has a cold, takes an herbal supplement, and gets better, we might think the pill cured her. But the cold could’ve just as likely gone away on its own. Without clinical studies, we’re just guessing.

Or if you have a headache and your friend says, “I put three drops of lemon oil on my wrists and my headache went away,” you might give it a try. What the heck, right?

Or if you have cancer and you’re afraid of dying, you might try anything to get better — even if it’s never been shown to be effective in a clinical trial, doesn’t make any sense how it might work in the first place, or you have to shell out thousands of dollars at a clinic in another country for treatment.

Choosing treatments for your illness is complicated by research that suggests many published studies — yes, scientific studies — are wrong.

Science isn’t infallible. But it is methodical and self-correcting. Over time, new studies either confirm past results or weed out the mistakes.

Not everyone has a strong background in science or clinical trials, so how are we supposed to decide which treatments work?

Hall offers what she calls her SkepDoc’s Rule.

“Before you accept any claim, try to find out who disagrees with it and why. That can be very illuminating,” she said.

Also, you can always ask your doctor for advice. But even with that, Hall suggests some level of skepticism.

People should “ask their doctor to provide evidence to support his or her recommendations,” said Hall, “and then they should check to see what others have said about that evidence.”